RESUMO
Background: Niche cells, regulating Spermatogonial Stem Cells [SSCs] fate are believedto have a reciprocal communication with SSCs. The present study was conductedto evaluate the effect of SSC elimination on the gene expression of Glial cell line-Derived Neurotrophic Factor [GDNF], Fibroblast Growth Factor 2 [FGF2] and KitLigand [KITLG], which are the main growth factors regulating SSCs development andsecreted by niche cells, primarily Sertoli cells
Methods: Following isolation, bovine testicular cells were cultured for 12 days on extracellularmatrix-coated plates. In the germ cell-removed group, the SSCs were removedfrom the in vitro culture using differential plating; however, in the controlgroup, no intervention in the culture was performed. Colony formation of SSCs wasevaluated using an inverted microscope. The gene expression of growth factors andspermatogonia markers were assessed using quantitative real time PCR
Results: SSCs colonies were developed in the control group but they were rarely observedin the germ cell-removed group; moreover, the expression of spermatogoniamarkers was detected in the control group while it was not observed in the germ cellremovedgroup, substantiating the success of SSCs removal. The expression of Gdnfand Fgf2 was greater in the germ cell-removed than control group [p<0.05], whereasthe expression of Kitlg was lower in the germ cell-removed than control group [p<0.05]
Conclusion: In conclusion, the results revealed that niche cells respond to SSCs removalby upregulation of GDNF and FGF2, and downregulation of KITLG in order to stimulateself-renewal and arrest differentiation